Phosphorus aromatic compounds



of Delaware Filed May 20, 1960, Ser. No. 30,428

No Drawing.

4 Claims. (Cl. 260-6tl65) This invention relates to novel phosphorus compounds. More particularly, it relates to novel ethylenically unsaturated secondary phosphine compounds. This application is a continuation in part of patent application S.N. 813,327, filed May 15, 1959, now abandoned.

The technology of phosphorus polymers has heretofore remained relatively undeveloped. However, phosphorus polymers are growing increasingly attractive for use in specialized applications wherein their novel properties may be advantageously utilized.

It is an object of this invention to provide novel phosphorus compounds.

Another object is the provision of novel secondary phosphine compounds containing ethylenic unsaturation and a process for their manufacture.

A further object is the provision of a new class of polymerizable phosphorus monomers.

These and other objects are attained by reacting substantially equimolar proportions of an alkali metal salt of a primary organophosphine and an ethylenically unsaturated aromatic organic halide as hereinafter described in a substantially oxygen-free reaction system wherein at least one of the reactants is dissolved in an inert solvent.

The following examples are given in illustration of the invention and are not intended as limitations thereon. Where parts are mentioned they are parts by weight.

Example I Twenty-seven parts (about 0.2 mol) of sodio-phenylphosphine are dissolved in a mixture of 100 ml. of liquid ammonia and 50 ml. of absolute ether maintained at a temperature of about 70 C. in a stirred reactor under a nitrogen atmosphere. A solution of 28 parts (about 0.2 mol) of 4-chlorostyrene dissolved in 75 ml. of absolute ether is slowly charged to the reactor while maintaining a reaction temperature of about 60J;5 C. After all of the 4-chlorostyrene solution has been charged, the ammonia and ether are removed by distillation under a nitrogen atmosphere. The remaining fluid is vacuum distilled to purify the product which is a liquid containing about 14.5% of combined phosphorus by weight. Infrared analysis reveals absorption characteristic of ethylenic unsaturation as well as of phosphorus-hydrogen and of phosphorus-phenyl linkages, indicating the product to be 4-(phenylphosphino)styrene.

Example 11 Eleven parts (about 0.2 mol) of lithio-methylphosphine are slurried in 50 ml. of absolute ether in a stirred reactor equipped with a reflux condenser. The mixture is placed under a nitrogen atmosphere and cooled to a temperature of 70 C. A solution of 28 parts (about 0.2 mol) of 4-chlorostyrene dissolved in 75 ml. of absolute ether is slowly charged to the reactor while maintaining a reaction temperature of about 60i5 C. After all of the 4-chlorostyrene solution has been charged, the ether is removed by distillation under a nitrogen atmosphere. The remaining fluid is vacuum distilled to purify the product which is a liquid containing about 20.2% of combined phosphorus by weight. Infrared analysis reveals absorption characteristic of ethylenic unsaturation as well as of phosphorus-hydrogen and of phosphorus-phenyl bondings, indicating the product to be 4-(methylphosphino)styrene.

tates Patnt 2 Example 111 Thirteen parts (about 0.1 mol) of potassio-n-butylphosphine are mixed with ml. of dioxane in a stirred reactor equipped with a reflux condenser. The mixture is heated to reflux (circa 101 C.) under a nitrogen atmosphere. Maintaining the reaction system at reflux, a solution of 16 parts (about 0.1 mol) of 3-chlorophenyl vinyl ether dissolved in 80 ml. of dioxane is slowly charged to the reactor. After all of the 3-chlorophenyl vinyl ether solution has been charged, the dioxane is removed by distillation under a nitrogen atmosphere. The remaining fluid is vacuum distilled to purify the product which is a colorless liquid containing about 14.8% of combined phosphorus by weight. Infrared analysis reveals absorption characteristic of ethylenic unsaturation as well as of ether linkages and of phosphorushydrogen and phosphorus-phenyl linkages, indicating the product to be 3-(n-butylphosphino)phenyl vinyl ether.

Example IV Twelve parts (about 0.1 mol) of lithio-mhexylphosphine are slurried in 75' ml. of toluene in a stirred reactor equipped with a reflux condenser. The mixture is heated to reflux (circa 111 C.) under a nitrogen atmosphere. Maintaining the reaction system at reflux, a solution of 23 parts (about 0.1 mol) of 4-chlorophenyl alphaphenylvinyl ether dissolved in ml. of toluene is slowly charged to the reactor. After all of the 4-chlorophenyl alphaphenylvinyl other solution has been charged, the precipitated salt is removed by filtration and the toluene is removed by distillation of the filtrate under a nitrogen atmosphere. 'The resulting solids are dissolved in hot benzene (circa 75 C.) and are reprecipitated by cooling the benzene solution to about 0 C. The product is a waxy solid contain ng about 10.0% of combined phosphorus by weight. Infrared analysis reveals absorption characteristic of ethylenic unsaturation as well as of ether linkages and of phosphorus-hydrogen and phosphorus-phenyl linkages, indicating the product to be 4-(nhexylphosphino)phenyl alphaphenylvinyl ether.

The ethylenically unsaturated organic halides employed in the practice of this invention correspond to general formulae of the group consisting of:

In each of the above formulae, X is either bromine, chlorine or iodine and Ar is a divalent aromatic residue contain from 6 to 14 carbon atoms. R may be either a hydrogen, a methyl or a phenyl radical.

Therefore, the 4-chlorostyrene, 3-chlorophenyl vinyl ether and 4-chlorophenyl alpha-phenylvinyl ether employed in the examples may be replaced, for example, with one of the following ethylenically unsaturated halides With equivalent results:

1) A haloaromatic vinylidene compound including ortho-, metaand para-halo-styrenes, -alpha-methylstyrenes and -alpha-phenylstyrenes such as 2-chlorostyrene, 4-bromostyrene, 4-iodo-styrene, 3-iodo-alphamethylstyrene, 4-chloro-alpha-methylstyrene, 2 iodoalpha-methylstyrene, 4 bromo-alpha-phenylstyrene, 3- chloro alpha-phenylstyrene, 3-methyl-4-chlorostyrene, etc.; halo-naphthalene compounds such as 1-chloro-8- vinyl-naphthalene, 1 bromo-4-vinyl naphthalene, 3- chloro-7-vinyl-naphthalene, 1 iodo-8-isopropenyl-naphthalene, 1-bromo 4-isopropenyl-naphthalene, l-ohloro-4- alpha-phenylvinyl-naphthalene, 2-bromo-7-alpha-phenylvinyl-naphthalene, etc; and halo-anthracene compounds such as 9-chloro-ltl-vinyl-anthracene, l-bromo-8-vinyl anthracene, l-iodo-4-vinyl-anthracene, 3-chloro-5-vinylanthracene, 9 bromo-lO-isopropenyl anthracene, lchloro-S-isopropenyl-anthracene, l-bromo-4-isopropenylanthracene, 9-bromo-lO-alpha-phenylvinyl-anthracene, l- .chloro-4-alpha-phenylvinyl-anthracene, etc., and

(2) A haloaromatic vinylidene ether including such vinyl ethers as 4-bromophenyl vinyl ether, 2-methyi-4- ohloro-phenyl vinyl ether, 2-iodo-phenyl vinyl ether, 1- vinyloxy-4-chloro-naphthalene, l-vi-nyloxy 8 bromonaphthalene, 1 vinyloxy-4-iodo-anthracene, 9-vinyl'oxy- -bromo-anthracene, 1-vinyloxy-8-chloro anthracene, etc.; such isopropenyl ethers as 4-chloro-phenyl isopropenyl et-her, Z-br'omophenyl isopropenyl ether, Z-methyl- 3-chlorophenyl isop-ropenyl ether, l-isopropenyloxylbromo-naphthalene, Z-isopropenyloxy-7-chloro naphthalene, 9 isopropcnyloxy-lO-bromo-anthracene, l-isopropenyloxy-4-chloro-anthracene, 2 isopropenyloxy 3- chloro-anthracene, etc. and such styryl ethers as 4- bromophenyl aipha-phenylvinyl ether, 3-chloro-phenyl alpha phenylvinyl ether, 1 alpha-phenylvinyloxyiohloro naphthalene, 2 alpha-phenylvinyloxy-7-brom0- naphthalene, 9-alpha-phenylvinylox-l0-chloro-naphtha- V substantially equimolar proportions of the alkali metal and the appropriate primary organophosphine in a. highly polar but inert solvent, e.g., liquid ammonia or sulfur dioxide, under an inert atmosphere. This type of synthesis is described in greater detail by C. H. S. Hitchcock and F. G. Mann in the Journal of Chemical Society, June 1958 (429), pp. 2081-2086.

The unsaturated secondary phosphine compounds which form the subject of this invention correspond to general formulae of the group consisting of:

( I R i i H-:i-AIC=CH2 and (b) R R1 HliArO( 3=CH2 depending upon the ethylenically unsaturated organic halide and primary organophosphine employed. In each of these formulae, Ar, R and R are radicals as heretofore disclosed.

These compounds are prepared by reacting substantially equilmolar proportions of an alkali metal salt of a primary organophosphine and an ethylenica-lly unsaturated organic halide, of the classes heretofore disclosed, under an inert, e.g., nitrogen, atmosphere. The reaction is efiected in the presence of a solvent inert to the reactants. Suitable solvents include, for example, hydrocarbons such as benzene, toluene, xylene, hexane, cyolohcxane, etc. or polar solvents such as ether, dioxane, tetrahydrofuran, liquid ammonia, liquid sulfur dioxide, etc. It is not necessary that both reactants be soluble textiles, wood, etc.

. Zel'le.

in the solvent employed. However, it is preferred to employ a polar solvent, or a mixture of solvents, in which both reactants are soluble. The reaction temperature employed is usually dictated by practical require ments since the reaction proceeds efiiciently at all temperatures. When liquid ammonia or sulfur dioxide are employed as the solvent, sub-zero temperatures below the boiling points of such are generally required. Superatmospheric pressures may optionally be employed to raise the boiling point of the solvent employed.

The final reaction mixture is comprised of the desired ethylenically unsaturated secondary phosphine in admixture with solvent and residual reactants. Precipitated metal halide is also present. Recovery of the product is accomplished according to conventional techniques. The precipitated salt may be removed by, e.g., filtration or decantation. The solvent and residual reactants may be removed, for example, by distillation, either under vacuum or under an inert atmosphere; The ethylenically unsaturated secondary phosphines so produced are generally fluids. However, those of higher molecular weight, especially those containing two or more phenyl groups, may be crystalline or waxy solids.

These ethylenically unsaturated secondary phosphines are useful as antioxidants for incorporation into such resinous compositions as e.g., synthetic or natural rubber, styrene or substituted styrene polymers, vinyl ester polymers such as polyvinyl chloride, polyvinyl acetate, etc, acrylic polymers such as polyacrylonitrile, polymethylmethacrylate, etc. They may also be polymerized to form linear polyphosphines which are generally flameresistant resins useful as flameprooiing agents for paper, Such resins may also be molded, extruded or cast as sheets, films, tubing, etc. for, e.g., electrical insulation, fire barriers, surface coatings, etc.

Example V Forty parts of the 4-(phenylphosphino)styrene prepared in Example I are charged to a 250 ml. glass flask equipped with a reflux condenser. The monomer is placed under a nitrogen atmosphere and is then irradiated with ultraviolet light for about 20 hours at room temperature. The resulting solid material is dissolved in 150 ml. of a 1:l by weight mixture of acetone and ben Zene, which solution is then poured into an excess of absolute ether to precipitate the polymer. A hard, clear, glass-like polymer containing about 14.5% phosphorus by weight is obtained. Upon testing for flammability by holding the polymer in the flame of a Meeker burner until it ignites, the polymer is found to be sel'fcxtinguishing.

Example VI A rectangular chip of ponderosa pine measuring about x 1" x 3" is immersed for 4 hours in 80 ml. of a 50% by weight solution of the 4-(phenylphosphino)styrcne polymer obtained in'Example V dissolved in ben- The pine chip is then heated in an air oven at 80 C. for about 3 hours to remove all adsorbed solvent. Testing for flammability by holding the pine chip vertically in they flame of a Meeker burner until it ignites, the chip is found to be self-extinguishing.

It is obvious that many variations may be made in the products and processes set forth above without departing from the spirit and scope of this invention.

What is claimed is: r

1. An ethylenically unsaturated secondary phosphine corresponding to a general formula selected from the group consisting of: V

n i -Ar-b=om and (b) R R,

n-i-ako i orn wherein, each of the above formulae, Ar is a divalent aromatic residue containing from 6 to 14 carbon atoms, R is a hydrocarbon radical containing from 1 to 12 carbon atoms and R is a radical selected from the group consisting of hydrogen, methyl and phenyl radicals.

2. 4-(phenylphosphino) styrene.

3. 4-(methylphosphino)styrene.

4. A process for preparing an ethylenically unsaturated secondary phosphine corresponding to a general formula selected from the group consisting of:

which comprises reacting substantially equirnolar proportions of an alkali metal salt of a primary or-ganophosphine corresponding to the general formula:

and an ethylenically unsaturated organic halide corresponding to a general formula selected from the group consisting of:

and

in a substantially oxygen-free reaction system with at least one of the reactants dissolved in an inert solvent; wherein, in each of the above formulae, M is an alkali metal radical, X is a halogen radical selected from the group consisting of bromine, chlorine and iodine, Ar is a divalent aromatic residue containing from 6 to 14 carbon atoms, R is a hydrocarbon radical containing from 1 to 12 carbon atoms and R is a radical selected from the group consisting of hydrogen, methyl and phenyl radicals.

No references cited. 

1. AN ETHYLENICALLY UNSATURATED SECONDARY PHOSPHINE CORRESPONDING TO A GENERAL FORMULA SELECTED FROM THE GROUP CONSISTING OF: 